Unified method and apparatus to simplify telephone area code dialing

ABSTRACT

A method and apparatus for unified overlay dialing enables simplified telephone dialing to occur within a standard overlay area and eliminates disruption dealing with area code saturation. Each three-digit area code within an overlay area is associated with a single-digit suffix, with the parent area code obtaining the suffix &#34;0&#34;. Intra-overlay area dialing then proceeds on the basis of a seven digit number plus a one-digit suffix, rather than a full 1+10-digit number. For dialing to the parent area code from within the overlay area, the suffix may be omitted entirely, and the expiration of a suitable timing delay causes the seven digit number provided to be dialed into the original (parent) area code. This method can be implemented in connection with a telephone company central office switch, a modified custom calling service or be made accessible to individual telephone subscribers using computerized customer premises equipment. It can also be used to simplify dialing in non-overlaid situations.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.60/047,747, filed May 28, 1997.

FIELD OF THE INVENTION

This invention relates generally to the field of telephone numberingsystems, and particularly, discloses a simplified method of dialing inconnection with telephone area code overlays and area codes in general,and an associated apparatus that enables individual telephonesubscribers to utilize this simplified dialing method independently ofthe adoption or non-adoption of this method by the telephone companiesand pertinent government agencies.

BACKGROUND OF THE INVENTION

As population increases, and as the use of the telephone system grows toaccommodate new, non-traditional uses of switched telephone connectionssuch as facsimile transmission, internet traffic, and related non-voice,data applications, the existing 7-digit numbering scheme for localcalling is coming under increased stress. Under the existing NorthAmerican numbering plan, which addresses any given telephone location by(NXX)N23-4567, where N is a digit from 2 to 9, X is any digit from 0 to9, NXX is an area code, and N23-4567 designates a 7-digit phone numberwith central office prefix N23, a single area code, in theory, can onlyaccommodate up to 8 million numbers (1 million based on the last sixdigits, times 8, for a first digit between 2 and 9). This is furtherrestricted, since any given central office prefix N23, which isaddressed through a single central office, and which can accommodate upto ten thousand numbers, may be under-utilized, for example, in a ruralarea where a central office of given N23 prefix may only serve a fewhundred or a few thousand telephones. With competition developing inlocal loops, the so-called "CLECs" (Competitive Local Exchange Carriers)are obtaining given N23 prefixes for their own central offices, exertingfurther pressure on our numbering supplies. The depletion of availablenumbers in an area code is called "Area Code Exhaust". The process ofreplenishing the number supply in a numbering plan area is called "AreaCode Relief".

Current solutions for Area Code Relief (splits and standard overlays)create, rather than solve, problems for customers. Recently, thewidespread use of these methods has resulted in what can readily bedescribed as a "National Area Code Disaster." Our dialing landscape hasbeen damaged, and this damage has been expensive and disruptive forbusinesses and consumers. Some of the impacts from these current reliefmethods are outlined below.

FIGS. 1, 1A illustrate an established area code (818, as an example)before being impacted by area code relief. One solution which has beenutilized, is so-called area code splitting, which is illustrated byFIGS. 2, 2A. In this solution, a geographic boundary is cut through theexisting area code, the original area code (e.g. 818) is maintained onone side of the boundary, and a new area code (e.g., 626) is establishedon the other side of the boundary. This approach, however, is highlydisruptive to telephone users both within and outside of the affectedarea code. Telephone owners in the new 626 area code effectively changeto a new phone number overnight, and are forced to reprint letterheads,business cards, advertisements, directory listings, etc., in order toadvise callers of their new area code. Callers both inside and outsidethe affected area code must adjust to the disrupted dialing patterns,including becoming familiar with the new numbers. Autodialers callinginto the new area code, and from the new area code into the old areacode, must be reprogrammed. Perhaps the only aspect of local callingwhich survives, is that callers within the old area code and the newlycreated area code can still use a 7-digit number to dial othertelephones within their own area code's boundaries. However, callsacross the new border between the old area code and the new area codenow require 1+10-digit dialing, and disruption occurs both within andoutside of the pertinent area codes. Overall, area code splitting iscumbersome, disruptive, and expensive.

An area code split forces half of the customers in the affected area togive up their existing phone numbers, cuts abbreviated (7 digit) dialingareas in half, and permanently disrupts established dialing patternsboth within the affected area and into the affected area from everywhereelse in the world. The overall cost just for mopping up after a singlearea code split is estimated to be over 40 million dollars (thisincludes updating signs and stationary, reprogramming of burglar alarms,fire alarms and other auto dialing systems, notifying customers andfriends of number changes, modifying local phone switches, etc.). Thisreshuffling of phone numbers creates confusion for customers, resultingin numerous missed or misdialed phone calls for many years to come.

Another solution, illustrated by FIGS. 3, 3A, is the standard overlaymethod. In this method, instead of the geographic split of FIGS. 2, 2A,the new area code is "overlaid" on top of the original area code. Theresult is a form of "subscription-based," rather than "geographic"splitting. That is, once the original (or "parent") 818 area code (forexample) nears saturation, many new local telephone subscribers will begiven numbers in the new (or "child") area code, such as 626 in thisexample. Over time, telephones with the 626 area code and telephoneswith the 818 area code will be intermingled throughout the geographicarea described by the original 818 area code's boundaries. A user whofirst subscribed to a telephone connection in the 818 area code beforesaturation (i.e., exhaust), and who subscribes after saturation, e.g.,to a second telephone connection to run a facsimile machine, wouldpossibly obtain a 626 number for the facsimile line, and thus could havelines with two different area codes under the same roof. Over time, theoverlay area (i.e., that area served by both the parent (e.g. 818) andthe child (e.g. 626) area codes) would have telephone numbers with botharea codes interlaced throughout it, and a call across the street, oreven within the same building, could well involve two (or more) areacodes.

The advantage to this approach, is that nobody ever needs to "change"their telephone number. Existing subscribers keep their original (the"parent") area code, while new subscribers might obtain a number fromthe new ("child") area code. With this method, no one ever has to updateadvertising, letterhead etc., to inform customers and friends about thearea code change, because only new subscribers would receive service inthe new area code. In addition, this approach is transparent to peopleoutside of the overlay area, whether receiving calls from, or dialinginto, the overlay area. Thus, this overlay method is much lessdisruptive to existing subscribers than is the area code split of FIGS.2, 2A.

The disadvantage of this method, is that it severely disrupts localdialing patterns. In particular, as illustrated, every call, evenlocally, now becomes a 1+10-digit call, in which the caller must supplyan area code even for calls right across the street, or to the officeupstairs in the same building. Thus, autodialers must be reprogrammed,directory listings must be reprinted with at least 10-digit numbers,small children or elderly or handicapped persons must learn or re-learna more difficult dialing technique, and the simplicity of 7-digitdialing stands in peril of extinction. While the FCC mandate for dialingparity in overlays has been interpreted to require that 1+10 digitdialing be used for all overlay dialing, it would be desirable toachieve this required parity, if possible, by dialing fewer than 1+10digits.

In summary, using standard overlays for relief also creates hardship forcustomers. Existing dialing patterns are disrupted for all customers inthe affected area. Seven (7) digit abbreviated dialing is abandoned forless convenient (and very unpopular and controversial) 1+10 digitdialing. For all calls in a standard overlay scenario, the area codemust be dialed before the 7 digit number, creating difficulty forcustomers--especially children, elderly, and handicapped. Many peoplehave expressed concern that dialing multiple area codes for calls withina single geographic region will create a feeling of disunity for thearea. The shift from 7 digit to 1+10 digit dialing also necessitatesreprogramming for all burglar alarms, fire alarms and other automaticdialing systems which had previously been programmed with 7 digitnumbers. Incomplete calls will occur when 7 digits are dialed withoutthe area code, and it is likely that the wrong area code will often beused by mistake, which happens today even where area codes are notoverlaid. And, the likelihood of misdialing at least one out of 10 or 11digits is significantly greater than when only 7 digits are dialed(expect an increase of 42% for 10 digits and 57% 1+10 digits).

By disrupting established dialing patterns, area code splits andstandard overlays cause hardship, confusion and expense for customers,and prompt numerous misdials and wrong numbers.

It would be desirable if area code relief could be achieved with aminimum of disruption and expense. For a solution to be "preferred" itwould have to satisfy both the needs of the customer and therequirements of the telecommunications industry.

OBJECTS OF THE INVENTION

It would therefore be desirable to have a numbering plan which greatlyreduces the confusion and inconvenience that is associated with havingmultiple area codes within individual neighborhoods and households.

It would further be desirable to have a plan which is non-disruptive toexisting 7 digit and 1+10 digit dialing patterns, wherein no one is putin jeopardy by a change to their local dialing plan (especially childrenand elderly/handicapped persons), and existing auto dialers can completecalls without reprogramming.

It would further be desirable to have a plan which reduces thelikelihood that the new overlay area code will be a stigma for newbusinesses.

It would further be desirable to have a plan which ensures that costs tobusinesses and disruption overall will be kept to a minimum.

For customers, a preferred solution would: be consumer friendly; allowcustomers to keep their existing area codes and phone numbers; preserveall dialing patterns to established phone numbers (backwardcompatibility); minimize impact on children and the elderly; avoidcostly reprogramming of existing burglar alarms, fire alarms and otherauto-dialers; save consumers, businesses and telephone companies moneyoverall; and provide long term, non-disruptive relief to exhausted areacodes.

For the telecommunications industry, a preferred solution must: offerbenefit to customers; be competitively neutral; be technically workable;be cost effective to implement; be built on top of the existing networkso that past investment is not discarded; and limit all costs andchanges in "dialing, switching and programming" to the geographic areain which the solution is implemented.

It would be difficult to argue against. an alternative which met thesespecifications, yet it is natural that controversy might surround it.

SUMMARY OF THE INVENTION

The invention disclosed herein is based on the standard overlay methodof FIGS. 3, 3A, but establishes a unified dialing plan for theseoverlays which eliminates the need for 1+10-digit dialing within anoverlay region. It avoids the disruption of area code splitting asdescribed above in (connection with FIGS. 2, 2A, and it also avoids theneed to dial 11-digit numbers within an overlay area as in FIGS. 3, 3A.

In particular, within an overlay area, the original (parent) area codeis represented by a single-digit suffix "0", and the child area code isrepresented by the single digit suffix "1". Subsequent child area codescan be numbered 2 through 9, before the need arises to add a seconddigit to the suffix. For anyone within the overlay area (from either theparent or a child area code) who is dialing to a number in the parentarea code, all that is required is to dial the original 7-digit localnumber, followed by the single-digit suffix "0". In reference to FIG. 6,the "0" suffix causes computerized telephone number conversion device 1(whether a central office switch 2, a custom calling service, or acustomer premises equipment device 3, 4) to signal the seven digitnumber using the parent area code. Additionally, by default, if thefirst 7 digits are dialed and an eighth digit is not dialed beforeexpiration of a predetermined timing delay, the device 1 will assume (bydefault) that the eighth digit is a zero, and the call will be routed tothe seven digit number that was dialed, in the parent area code.

For anyone within the overlay area (from either the parent or a childarea code) who is dialing to the (first) child area code, all that isrequired is to dial the original 7-digit local number, followed by thesingle-digit suffix "1", which represents the (first) child area code.This suffix will cause the telephone number conversion device to signalthe given 7-digit number, but in the (first) child area code. In short,using the earlier examples, a "0" suffix or a timing delay without asuffix causes the seven digits provided to be dialed into the 818(parent) area code, while a "1" suffix causes the seven digits providedto be dialed into the 626 (first child) area code.

This system does not in any way affect or change the standard overlaymethod of FIGS. 3, 3A, but rather provides a simplified method fordialing within and between overlaid area codes. Full 1+10-digit dialingcould still be used by someone wishing to do so, but simplified dialingusing only 8 digits (or 7 digits with a timing delay for dialing to theparent area code) can likewise be used, since eachseven-digit-plus-suffix combination can be mapped precisely into acorresponding 1+10-digit number. Ideally, this method would beimplemented in central office switching equipment and would becomeadopted as a unified dialing plan.

Alternatively, or in supplement to this, this method can be implementedthrough customer premises equipment (CPE) that takes an 8-digit number(or a 7-digit number plus timing delay), and converts (maps) it into theappropriate 11-digit number ("1"+"3 digit area code"+"7 digit telephonenumber"). The CPE would then send the 11 digits to the central officeswitch for signalling, while only requiring the caller to have dialed 7or 8 digits to place the call.

In brief, the "unified method and apparatus to simplify telephone areacode dialing" according to the invention comprises a dialing systemwhich:

1) Allows for optional (not mandatory) 1+10 digit dialing within andbetween all area codes in the geographic overlay area;

2) Unifies all area codes in the geographic overlay area with a simple 8digit (7+suffix) dialing system. The suffix represents one of tenpossible overlaid area codes with `0` being the original area code, `1`being the first overlaid area code, `2` being a future second overlaidarea code, etc. When the appropriate device (a switch, custom callingservice or a computerized CPE device) receives the full 8 digits, ittranslates the number into a traditional 10 digit number (3 digit areacode+7 digit phone number) and passes it through the network as if thenumber had been originally dialed as 1+10;

3) Preserves established `7 digit style`, dialing to all phone numbersin the original area code from any area code within the geographicoverlay area, by use of a "timing delay."

Functionally the network switch, custom calling service or CPE will belooking for either 1+10 style numbers or 7+suffix style numbers. Withdefault dialing, if only 7 digits are dialed, after an appropriatetiming delay the switch will assume that `0` is the intended 8th digitand will put the call through to the original area code of the overlayarea. In this way, backward compatibility is achieved for dialing to`pre-relief phone numbers` from any area code in the geographic overlayarea, and the system appears completely non-disruptive to the customer.In short, the invention offers an advanced 8 digit dialing system basedon and fully compatible with overlay groupings, yet it is backwardcompatible with all established dialing patterns to existing(pre-relief) phone numbers.

BRIEF DESCRIPTION OF THE DRAWING

The features of the invention believed to be novel are set forth in theappended claims. The invention, however, together with further objectsand advantages thereof, may best be understood by reference to thefollowing description taken in conjunction with the accompanying drawingin which:

FIGS. 1, 1A show the established dialing patterns in an area code priorto implementing area code relief.

FIGS. 2, 2A show the prior art method of area code splitting, whichdisrupts established dialing patterns.

FIGS. 3, 3A show the prior art method which employs standard overlays,which also adversely impacts established dialing patterns, and how itsoverlaid levels are not united by a distinctive dialing plan.

FIGS. 4, 4A show a unified dialing plan for overlays in accordance withthe invention, which is non-disruptive to established dialing patternsand which unifies all levels of the overlay area with a simple 8 digitdialing system.

FIG. 5 is a functional (flowchart) diagram of the unified dialing planfor overlays of FIGS. 4, 4A.

FIG. 6 is a chart illustrating the number allocation method according tothe invention.

FIG. 7 is a functional (flowchart) diagram of an alternate embodiment ofthe invention.

FIG. 8 is a chart illustrating the number allocation method according toalternate embodiment of the invention of FIG. 7.

FIGS. 9A-9C are schematic input/output diagrams illustrating acomputerized apparatus according to the intention, and the use of thisapparatus in connection with a telephone company switch and a customerpremises equipment device.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION

FIGS. 1, 1A, 2, 2A, 3, and 3A illustrate prior art methods of allocatingarea codes and dialing, as was discussed earlier in the background ofthe invention.

FIGS. 4, 4A illustrate a dialing system(m which supports theimplementation of overlays for area code relief by eliminating thepublic's main objections to them. The plan preserves established dialingpatterns to existing pre-relief) telephone numbers, and unifies alllevels of an overlay area with a consistent abbreviated dialing method.Long term relief is provided for exhausted area codes without impactingdialing, switching or software in any other areas of the North AmericanNumbering Plan (NANP).

Defining the following terms will be helpful for the discussions thatfollow:

parent level of overlay: the original area code (in these examples the818 area code).

child level of overlay: a new overlaid area code (in these examples the626 area code is the first child level).

overlay area: a single geographic area which contains the parent leveland all of the child overlay Levels.

intra-overlay area calls: refers to calls where the origin and thedestination area codes both reside within the geographic overlay area.

abbreviated dialing: dialing which requires fewer than 11 digits tocomplete (abbreviated dialing within an area code is typically 7digits).

timing: as used in this Unified Dialing Plan, a predetermined interval(probably 3-4 seconds) invoked after the 7th digit of a phone number isdialed. If this interval elapses and no further digits have beenentered, the phone system switch will run an analysis on the 7 digitnumber that has been dialed. This technique will allow customers to dialvalid phone numbers of varying lengths (7 or 8 digits).

In accordance with the invention, an ovrerlay is implemented such thatlocal dialing within the overlay area is facilitated by:

`7 digit`+timing dialing for intra-overlay area calls directed to theparent level of the overlay from any level of the overlay. This ensuresthat dialing patterns to existing numbers (parent level numbers) are notdisrupted with the introduction of an overlay, and can continue to bedialed with 7 digits plus a brief wait.

`8 digit` (7+suffix) dialing for intra-overlay area calls directed toany level of the overlay (parent or child). This is a `7+x` system,where the 8th digit is a suffix and acts as an overlay selector. Eacharea code within the overlay area is assigned a unique identifier, whichis to be used as the `8th digit suffix` or `overlay selector` indialing. This feature unifies all levels of the overlay area withconsistent abbreviated dialing, regardless of the originating ordestination overlay area codes. The parent is assigned a "0" for theeighth-digit suffix, the first child is assigned a "1", and subsequentchildren are assigned "2" through "9". When only seven digits are dialedfollowed by the timing delay, it is assumed by default that the eighthdigit is a "0", and the call is routed accordingly.

1+10 digit dialing, as used in the standard overlay method, ispermissive, but not mandatory, throughout the entire overlay area. Every7 or 8 digit number has a unique correspondence with (mapping to) a 1+10digit number.

FIGS. 4 and 4A, and FIGS. 5 and 6, illustrate how these three dialingmethods are integrated in accordance with the invention. While this planis applicable to any area where an overlay might need to be implemented,for ease of illustration it will be described by example using 818 asthe original area code, and 626 as the first new `overlaid` (child)level.

Within the overlay area only (i.e., the example 818/626 overlay area),the suffixes for intra-overlay area dialing are determined as follows:All 818 numbers receive a suffix of `0` (representing the parent level).All 626 numbers receive a suffix of `1` (representing the first childlevel). Any future overlay levels receive a suffix of `2`-`9` in thatorder. This framework allows for easy future expansion when moretelephone numbers are needed.

Thus, for calls originating anywhere within the 818/626 overlay area,dialing 123-4567-0 (to the parent level) is fully equivalent to dialing1-818-123-4567, and indeed either style of dialing is valid and willsuccessfully place the call. Similarly, dialing 123-4567-1 (to the firstchild level) is fully equivalent to dialing 1-626-123-4567, and again,either style of dialing is valid and will successfully place the call.For dialing to a second child level within an 818/626/??? overlay area,with a second child area code designated by ???, dialing 123-4567-2 (tothe second child) is fully equivalent to dialing 1-???-123-4567, andagain, either style of dialing is valid and will successfully place thecall.

Further, all 818 (parent) numbers can also be reached from any level ofthe overlay area simply by dialing the original 7 digit number and thenwaiting for a short timing delay. This feature of the invention makesthe introduction of an overlay completely non-disruptive to the existingdialing patterns of the original area code.

For example, for calls originating anywhere within the 818/626/???overlay area, dialing 123-456, and then waiting for the timing delay isfully equivalent to dialing 1-818-123-4567. That is, 7-digit dialing,followed by the timing delay, defaults to the 7 digit number in theoriginal area code, which accommodates established 7 digit dialingpatterns to pre-relief phone numbers. For a switch-based implementation,the telephone industry and/or appropriate government agencies woulddetermine the appropriate length for this timing delay, which couldrange from perhaps 1 to 10 seconds, and ideally might be about 3 to 4seconds. The industry could also customize the length of the timingdelay on a customer-by-customer (number-by-number) basis. Thus, onecustomer might request that all calls dialed from his or her phone use a3 second delay. Another customer might similarly request an 8 seconddelay for calls from his or her phone. Finally, customer premisesequipment used to achieve this dialing functionality in a standardoverlay area can readily be programmed with the precise timing delaydesired by the user, using methods well-known in the art.

Other variations on the timing delay may be necessary in order to avoidmisdials. These variations night include: 1) When the child overlay isfirst implemented, there will not be many numbers in the new area code(same as a standard overlay), so the chances of too short of a delaycausing a misdial early on is very low. This might justify a relativelyshort timing delay at first implementation--say 3 to 4 seconds. As themonths go by--if warranted by frequent misdials--the delay could begradually increased as the new area code grows more populated. 2) A fewseconds after 7 digits have been entered, a recorded message could playthat would give instructions on how to input the 8th digit--"for 818area code--enter 0, for 626 area code --enter 1," etc. After a few moreseconds it might say "at the tone, your call will default to the 818area code . . . beep". 3) If certain numbers were consistentlymisdialed, those numbers might be selectively blocked from 7 digitdefault dialing--or people could request that they never receive any 7digit default calls. This would not harm the functionality of the plan.These customers would still be able to dial with 7 digit default(protecting auto dialers, burglar alarms, fire alarms, etc.), but theirown number would no longer be reachable that way. 4) Or, the 7 digitdefault method might serve only as a transition device during the first6 months to 1 year of implementation. If misdials do become problematic,it could be phased out altogether. This would still leave the overlayarea with a very functional and efficient 8 digit abbreviated dialingplan.

For calls originating within the overlay area, the telephone numberconversion device, whether in a telephone company switch, is a modifiedcustom calling service, or in customer premises equipment, would operateas follows: Once 7 digits are received, the call will be consideredlegal. However the number conversion device will wait an additionalpredetermined timing period for a possible 8th digit, which is the`overlay area code selector`. If the timing delay elapses before the 8thdigit is received, a suffix of `0` is assumed, and the 7 digit call willautomatically be directed to the 818 (parent) level of the overlay.

If 8 digits are received before the tiring delay elapses, the conversiondevice will analyze the number, examining the 8th digit first. If the8th digit is a `0`, the call will be directed to the 818 (parent) levelof the overlay. If the 8th digit is a `1`, the call will be directed tothe 626 (first child) level of the overlay.

If the predetermined `timing delay` elapses and less than 7 digits havebeen received, the call is considered abandoned, and the standard `tryagain` message is given.

Once the proper overlay level is determined and the call is routed tothe proper area code within the overlay area, the suffix is discarded,leaving a standard 7 (digit number to be routed by traditional 7 digitswitching logic. All of the above is readily implemented, using methodswell-known in the art, in the switching or custom calling service deviceat telephone company central offices, and/or in customer premisesequipment, by taking a 7 or 8 digit number and converting it into theappropriate 7 digit or 1+10 digit number, then signalling it to a normaltelephone company switch in a standard overlay, or even non-overlaid,situation.

To summarize, all `7 digit+timing` or `7 digit+suffix` calls areconverted to 1+10 or 7 digit numbers as appropriate, by the phone systemor by the customer premises equipment, and are then transparently routedto the proper overlay level. It is to be noted that 1+10 digit dialingfor intra-overlay area calls would also be supported, if that is how anindividual preferred to dial, but it would not be mandatory. As such,the dialing plan according to the invention integrates seamlessly withthe standard overlay method.

For local or toll calls originating within the overlay area, butdirected outside of that area, mandatory 1+10 digit dialing would beused. This requires no change whatsoever to the existing method ofplacing calls outside an overlay area. If someone in the overlay areawere to accidentally use the `1+10+x` format (because they had becomeaccustomed to dialing 8 digit phone numbers) it wouldn't matter becausein 1+10 dialing, all extra digits beyond 1+10 are ignored, just as theyhave always been.

For calls originating outside the overlay area which are directed intothe overlay area, standard 1+10 digit dialing would be used. If someonefrom outside the overlay area were to accidentally use the `1+10+x`format (because they were unclear as to the correct dialing rules in theoverlay area) it wouldn't matter because in 1+10 dialing, all additionaldigits are ignored. Again, this does not in any way change how someoneoutside the overlay area dials into the area.

The overlay method heretofore described integrates well with existingdirectory listing practices, because numbers within an overlay area canall be listed with 8 digits. Thus, for example, in the 818/626 telephonedirectories the numbers will be listed as follows:

818 number 999-3360-0

626 number 956-2200-1

213 number 213-462-2110 (out of `overlay area` number)

626 number 347-9426-1

818 number 883-6234-0

310 number 310-244-0177 (out of `overlay area` number)

In the above, 7 digits+`0`=818 area code; 7 digits +`1`=626 area code.Because no area codes would need to be listed for intra-overlay areaphone numbers, the `new` 626 numbers (which a new business might have)will not stand out as red flags to customers looking for experiencedservices. Only out of `overlay area` phone numbers would stand out, thesame as they already do in current directories. This would not be a flagfor the business being "new," it would simply be a flag for the businessbeing out-of-area, as it is at present.

To further remind people how the system works, a sticker could besupplied to customers in the 818/62 area that said, e.g., "8 digitdialing supported: 7 digit phone number+0=818 area code; 7 digit phonenumber+1=626 area code."

The public can be informed about the use of the new plan, for example,with easy-to-understand language such as:

"For calls made from any telephone within the 818/626 overlay area toany phone number with an 818 area code (818 is the original (or"parent") level of this overlay area):

You may dial all 818 area code telephone numbers exactly as you alwayshave in the past using just 7 digits. After a short delay your call willgo through.

You may avoid this delay by dialing the 7 digit number +0.

For calls made from any telephone within the 818/626 overlay area to anyphone number with a 626 area code (626 is the first new (or "child")level of this overlay area):

You must dial all new 626 area code telephone numbers as the 7 digitnumber+1.

For calls made from any telephone within the 818/626 overlay area tophone numbers in area codes outside of the 818/626 overlay area:

Dial 1+area code+7 digits--the same as you would before the overlay wentinto effect.

For calls made from area codes outside of the 818/626 overlay area toany area code within the 818/626 overlay area:

Dial 1+area code+7 digits--the same as you would before the overlay wentinto effect."

This plan addresses customers' objections to using overlays which theyfear would result in confusion and/or the inconvenience of having todial 11 digits just to call across the street.

To ease the public's transition to overlays, simple 7 digit dialing toall existing (pre-relief) parent level numbers is maintained (this isalso a benefit for children, the elderly/handicapped, and automaticdialing systems).

The plan allows for abbreviated `7 digit+suffix` dialing from and to anyphone within the entire overlay area, without affecting how 1+10 digitcalls `out-of`, `into`, or `within` the overlay area are handled. It isexpandable to 10 levels (0-9) of overlay within a single geographicdialing area, allowing for painless addition of many new numbers in thefuture.

Additionally, the new style of directory listings which this dialingplan permits won't be a disadvantage for new businesses.

For the public, this plan will have the psychological appeal of being anew `high tech` solution to the challenges presented by splits andstandard overlays. It responds to all of the public's concerns aboutoverlays, and will leave citizens and businesses with a feeling thatsomething is finally being done to protect them from the expense anddisruption that traditionally comes with area code exhaust and relief.

When the advantages of this plan are weighed against the disadvantagesof area code splits and standard implementations of overlays (expense,disruption, confusion, inconvenience, permanent impact on the size ofgeographic dialing areas, etc.), this unified dialing plan for overlaysclearly makes sense as a solution for both the short and the long ter.

This system can be applied to any area that is faced with the need tointroduce an overlay. If this system becomes a standard, over time largeareas of North America would be able to locally take advantage of thisplan without affecting how any `out of area` or `into area` dialing andswitching is handled.

In short, this numbering plan greatly reduces the confusion andinconvenience that is associated with heaving multiple area codes withinindividual neighborhoods and households. Because the plan isnon-disruptive to existing 7 digit and 1+10 digit dialing patterns, noone is put in jeopardy by a change to their local dialing plan(especially children and elderly/handicapped), and it ensures thatexisting auto dialers can complete calls without reprogramming. Thisplan reduces the likelihood that the new overlay area code will be astigma for new businesses. Finally, it ensures that costs to businessesand disruption overall will be kept to a minimum.

It is important to note that this plan according to the invention can beused even when there is not a unique original area code. In these cases,only the 8 digit "unifying" feature is of the plan would be implemented.This situation would occur if an overlay were implemented on top of twoexisting distinct area codes. In this case, the 7 digit default wouldonly be used as a transition vehicle for each of the original areacodes, and then would be phased out, leaving the 8 digit system inplace.

The 8-digit-only version of the plan could also be used where a standardoverlay has already been implemented. In these cases, the 7 digitfeature of the plan would not be used at all, but the 8 digit featurecould be implemented and save callers 3 digits on each call. The 8 digitfeature could also be used to tie together geographically distinct areacodes that will not be overlaid, simply as a way to avoid having to dial1+10 for out of area code calls.

Where two existing NPAs are overlaid, the transition would take place intwo phases. In the discussion following, Area Code A signifies either ofthe existing area coders, Area Code B signifies the other existing areacode, and Area Code C signifies the new overlay area code. Note, toavoid confusion with situations where there is only one original areacode, the `0` suffix should not be used in cases where there are two ormore original area codes.

In phase one, before implementing the overlay, each of the two existingNPAs would separately migrate from 7 digit to 8 digit dialing using the7 digit default as the transition vehicle (1+10 digit dialing withineach area code would also be enabled at this time). Area Code A wouldmigrate to 7 digit+`1` suffix, and Area Code B would migrate to 7digit+`2` suffix. In either case, 7 digit calls (with a delay) woulddefault to the area code of origin during the permissive period. It isimportant to recall that in this situation, the two area codes are inseparate geographic areas, so 7 digits can default to the area code oforigin without confusion. During this period it might be possible todial between the two area codes using either the 8 digit option orstandard 1+10 digit dialing.

In phase two, at the end of the permissive dialing period, each of theexisting area codes would have separately migrated to 8 digit or 1+10digit dialing for all calls, and the 7 digit default method will nolonger be available for either area code. At this point 8 digit dialingand 1+10 digit dialing would be available for all calls within andbetween Area Codes "A" and "B". The third area code would now beoverlaid and could immediately use 8 digit or 1+10 digit dialing for allcalls within the "A B C" Area Code Grouping. The 8 digit numbers in thisnew overlaid area code ("Area Code "C") would be 7 digit+`3` suffix.This results, finally, in all three area codes being unified with the 8digit dialing option. Naturally 1+10 digit dialing would also be anavailable dialing method, for anyone who wishes to use it.

Even if this plan is not adopted as a North American standard, itintegrates seamlessly with the existing standard overlay method, as wellas with established methods for dialing within and between non-overlaidarea codes. Thus it is possible for computerized customer premisesequipment (CPE), using methods well-known in the art, to operateaccording to the lower flowchart of FIG. 5, and thus convert 7 and 8digit numbers into the appropriate 1+10-digit numbers, and then transmitthese 11-digit numbers out to phone company switching equipment thatuses only the standard techniques for dialing within and betweenoverlaid and non-overlaid area codes. This CPE could optionally besupplemented with a set of "hot buttons" on the phone which would beprogrammed to specific 1+3 digit area codes. By pressing one of thesebuttons at the start of a call, one could dial a 1+10 digit phone numberwith only 8 key presses (hot button+7 digit number). Or, the 7 digitnumber plus 1 digit suffix method earlier described can be used, asdesired by the user. Users of such a CPE device, using programming"setup" methods that are well known in the art, could choose their ownsuffixes to associate with each area code within the overlay area, andcould determine for themselves which area code gets the "0" suffix andhence can be dialed merely by 7 digits plus a timing delay.Additionally, such a CPE device can work in situations other thanoverlays if a user wishes to enjoy abbreviated dialing between separatenon-overlaid area codes. Thus, for example, not limitation, a user canassociate a digit (e.g., 0 through 9) with the ten area codes he/shedials most often. Then, by dialing a seven digit number plus one of thearea code-associated digits, the user can achieve 8-digit dialing intoten different area codes. This CPE can be attached to a phone line andto a preexisting phone as an add-on module, or it can be integrateddirectly with the telephone as a unitary device. Use of the word"telephone" above, and throughout this disclosure, is intended andunderstood to include facsimile machines, autodialers, computers, andany other devices that can be connected to a phone line or a wirelessservice connection, and which can generate the tones and/or pulsesnecessary to place a telephone call.

It should be noted that while numbers in all of the area codes withinthe geographic overlay area can be reached by dialing either `7+suffix`or `1+10`, the `7 digit default` dialing option (which requires a timingdelay) applies only to numbers in the original area code and only underdefault conditions. On the surface this would seen to offer preferentialdialing to certain numbers (which would be counter to the FCC's mandatefor dialing parity in overlays). However, on closer examination itbecomes clear that very few people would intentionally take advantage ofthis option. Because of the timing delay when only 7 digits are dialedcustomers will quickly opt for dialing the 8th digit (in this case `0`)in order to complete calls in the most expedient way. This 7 digitoption is really only provided in order to ease the transition into anoverlay scenario, and to act as a safety nest for old "7 digit style"calls which would otherwise be lost. It provides an extremely longpermissive dialing period, (ensures that any phone number that had beendialed with 7 digits in the past could still be dialed the same way, andminimizes the need to immediately update auto dialers and databases.More than likely, (a short time after implementation of this invention),7 digit calls will only be initiated by auto dialers which had beenprogrammed pre-relief (i.e. alarm system auto dialers), and which aretypically difficult or costly for their owners to update. In short, froma dialing parity standpoint, 7 digit dialing plus a timing delay is on apar with 8 digit dialing and no timing delay, i.e., the dialing of aneighth digit and the waiting for a timing delay are equivalent with oneanother insofar as they might deter a user from choosing a serviceprovider for whom one option would be used over the other.

As has been mentioned several times, this invention can also beimplemented by telephone company switching equipment as a modifiedcustom calling service. It could be integrated into the network eitheras a general feature available to all customers as part of their basicmonthly service, or as a subscription based feature available only tocustomers who pay a monthly fee or a pay per use premium. As an example,if this custom calling service were activated when the customer entered*?? (where ?? are any two digits selected by a telephone company forthis purpose), the switch would be signaled that a 7 or 8 digit (ratherthan 1+10 digit) call is about to be dialed. But entering the *?? wouldof course reintroduce extra dialing digits which this invention isdesigned to eliminate, so other approaches might also be considered.

For example, not limitation, instead of initiating the custom service bydialing a *??, this service could be automatically triggered if thecustomer began his call with a "2" through "9". The custom service wouldthen "watch" as digits were entered, and "decide" what to do with anygiven number. Naturally 411, 911 and other special services wouldimmediately be released to the network after only 3 digits are entered.Seven (7) digit calls would not be released until after the timingdelay, and both 7 and 8 digit calls would be translated into the proper3 digit area code+7 digit phone number before entering the network.Calls beginning with a 0 or a 1 would not trigger this service, since itcould be assumed that these numbers were going to be dialed as full 1+10or 0+10 digit numbers (and thus would not be using 7 or 8 digitdialing). And, since a caller can always choose to dial with either thereduced-digit option, or the full 1+10 digit number, using 7 or 8 digitdialing might automatically be billed as a premium service, while theuse of full 1+10 digit dialing would be billed as a standard(non-custom) service.

If this dialing method is implemented by the phone companies as a customcalling feature, or through CPE, the customer might be able to specifythat any given area code is the "parent style" area code. This wouldallow for 7 digit default dialing to any area code of the customer'schoosing, and could be used for both overlaid and non-overlaidsituations. If Each customer could select which area code defaulted to7-digit dialing, then every customer would get to choose exactly onearea code for 7 digit dialing, and there would be no possible advantageor disadvantage to anyone, either placing calls or receiving calls. Thisfurther overcomes any concerns that may arise regarding dialing parity.

The same user-selectable approach can he used for the "child style" areacodes. Here, using a customized calling service, or CPE, each user couldspecify that a certain group of area codes is to be dialed with eitherone digit at the beginning of the dialing or one digit at the end, andthe user could specify which area codes are associated with whichdigits.

Further, the user could select one area code for pure 7 digit dialing(no timing delay). Thus, if a user wanted to still be able to make allof his or her 818 calls by only dialing 7 digits, the user would tellthe switch that any call placed by that user which doesn't start with a0 or a 1 will always be a call intended for the 818 area code. Anothercustomer might prefer to make 626 his or her special 7 digit area code.If this feature could be changed at will, the user could make his or herphone behave as if it were located in any area code, at any time. Aphone in California, for example, would be able to dial 7 digit numbersin a New York area code!

A display on the user phone or similar device could show what area codeis assigned as the special 7 digit area code (similar to the caller IDdisplay). A device or telephone similar to the "hot button" devicedisclosed earlier can also be included. Thus, when the user presses thehot button, it remains selected (or ON) until it is turned off, or untila different area code "hot button" is selected. In this way, afterchoosing an area code, all calls dialed afterwards may be dialed withonly 7 digits (not 8). This could make the user's telephone behaveexactly as it did before the overlay. Or, if the user wanted to placemany calls to the 202 area code, he or she could press or program the202 button, and from then on dial all calls to that area code using only7 digits. Similarly, an OFF switch can be provided, so that one canbypass any of these special dialing features. This would help new usersfeel "safe" with this device.

All of the above, it is again noted, can readily be implemented throughphone company switches, and/or through computerized CPE.

FIG. 9 illustrate a preferred embodiment of the underlaying computerizeddevice of the invention. FIG. 9a, using an 818/626/??? overlay area asan example, illustrates computerized is telephone number conversiondevice 1 which accepts the dialing tones of a 7 or 8 digit telephonenumber as input, determines by means of an association table which areacode to associate with each overlay selector (including timing delayexpiration with no selector, which defaults to the parent (e.g. "0")selector, and outputs a 1+10 digit number corresponding to the full1+area code+local number of the number being dialed. The direct,one-to-one mapping between 8-digit numbers and 1+10 digit numbersaccording to the invention makes the device 1 extremely simple toimplement using methods well-known in the art. Naturally, any time it isdetected that a "0" or a "1" is the first digit dialed (e.g., the callerdials 1-818-N23-4567), the conversion is deactivated, and the number asdialed is simply passed through conversion device 1 unaltered.Similarly, the association table would contain special numbers such as"911", "411", etc. that, if detected, are simply passed throughunchanged.

The modular device 1, in turn, easily integrates into a number ofsettings. As shown in FIG. 9b, it can easily be incorporated into atelephone company switch 2 (or a PBX-type system at a customer site),and can thus be used to detect incoming 7 or 8 digit numbers, convertthem into 1+10 digit numbers, and signal the full 1+10 digit numberassociated with the incoming 7 or 8 digit number. As noted earlier, thismay or may not be provided to the customer as a custom calling service.

In the CPE variation, module 1 is connected to an ordinary, ispreexisting telephone 3. It converts 7 or 8 digit numbers dialed at thetelephone keypad 5 into the correct associated 1+10 digit numbers, andthen sends these converted numbers to the telephone switch overtelephone line 6. Alternatively, telephone 3 and module 1 can beincorporated together into a unitary "enhanced" telephone 4, whichsimilarly converts the input 7 or 8 digit number into a 1+10 digitnumber and sends that number out over the telephone line 6. In eitherevent, this CPE device gives the telephone user the option to simplifyhis or her dialing whether or not the telephone company itself choosesto implement this invention systemwide. And, in the event the simplifieddialing of this invention is implemented as a custom (premium) callingservice, this CPE device enables the user to avoid paying the premiumfor this custom calling service, and at the same time enjoy the benefitsof this simplified dialing.

For all of these variations, programming means 7 are used to program andcustomize module 1, using methods well-known in the art. This caninclude establishing the relationships between overlay selectors andarea codes, setting the timing delay, programming "hot buttons" for theCPE device, etc.

Finally, the methods described above lend themselves as well to anon-disruptive method for what to do when all 800=8×10×10 of theoriginal 3 digit (NXX) area codes are used up. (N=2 through 9, X=0through 9.) This method involves introducing new 5 digit area codes,where the 4th digit will always be a 0 or a 1, and the fifth digit maybe 0 through 9. This will create a system for adding 800×2×10=16,000more area codes without disrupting how existing numbers are dialed.

In this method, all 800 original area codes will be able to be known aseither the NXX00 or as the original NXX. All new area codes will beNXX01-NXX09 or NXX10-NXX19

When the dialing doesn't start with a 0 or a 1, the telephone numberconversion device detects this and determines that the number is beingdialed without an area code prefix, so it will treat the call as aconventional 7 digit call, or a 7 or 8 digit call according to theinvention as heretofore described. If the dialing does start with a 0 or1, the telephone number conversion device detects this and determinesthat the number following will be either a 3 digit or 5 digit area code.

In this case, if the 4th digit that follows the `original 0 or 1` is nota 0 or a 1 (i.e., if it is a 2 through 9), then the telephone numberconversion device interprets this to mean that an original 3 digit areacode is being used, and the call will be able to be completed withoutdialing the full 5 digits for the area code. This takes advantage of thefact that standard 7 digit numbers are always in the form N23-4567,where the first digit N runs from 2 to 9. As such, this method isnon-disruptive for dialing to these original 800 established 3-digitarea codes, since a call to a number in these area codes will always beable to be completed the same as it is today--with a 1+XXX00+7 digitnumber--or--optionally, with a 1+XXX00+7 digit number.

If the 4th digit that follows the `original 0 or 1` is a 0 or a 1, thetelephone number conversion device will recognize that a 5-digit areacode is being dialed, will await the fifth number of the 5 digit area,and will then signal the seven digits provided thereafter into the given5-digit area code. That is, all new 5 digit area codes will berecognized because of the 0 or 1 in the 4th position, and these willonly be reachable by dialing the full 5 digit area codes.

While the use of a single-digit suffix will suffice for an overlay areaencompassing up to ten area codes (which should cover any overlaysituations likely to develop for the foreseeable future), if an overlayarea in the future were to include more than ten area codes, then atwo-digit suffix would be required. In essence, the single-digit overlaycodes would be supplemented with a second overlay selector code digit,enabling up to 100 area codes to coexist within one overlay area.Intra-overlay calling would then use either 7 digit plus timing delay, 8digit plus timing delay or 9 digit dialing, rather than just 7 digitplus timing delay or 8 digit dialing as described above. While it isunlikely that an overlay area will grow to cover more than ten areacodes anytime soon, such a two-digit suffix is nevertheless encompassedby this disclosure and its associated claims.

Irrespective of whether this system is uniformly adopted, CPE canreadily be programmed using methods well known in the art to enable atelephone user to enter area codes in accordance with the above.

An alternate embodiment of this invention illustrated by FIGS. 7 and 8involves implementing overlays in a manner which would create "child"area codes spawned from the original area code, but these new codeswould appear to actually share the original area code's name. To thenetwork, these area codes would be known as, for example, 818-A, 818-B,818-C, etc. This method would allow customers everywhere (even outsideof the overlay area) to be able to dial "1"+the 3 digit "818" areacode + an 8 digit (7 digit+X) number, and have the suffix digitdetermine the intended overlay (area code) level. As with the earlierembodiments, the original area code could have the suffix "0", and bedialable with either 1+3+7 digits+timing delay or 1+3+7+X. Within theaffected area, all calls could be made by dialing only 8 digits or 7digits+timing delay.

This alternate variation will in practice be transparent to the user,while in execution (at the switching level) it will be functionally thesame as a standard overlay. The 8th digit (0-9) will be treated as asuffix, and will determine which of the overlaid area codes is to beaccessed. The actual switching at the local level would still be basedon traditional 7 digit dialing. Customers in area codes which have notbeen overlaid in this manner, do not need to use 8 digit numbers whendialing local calls, or to use 1+3+8 digit numbers when dialing out ofarea calls, unless those calls are being sent to a multiple area code 8digit dialing region.

In this alternate variation, local calls for the multiple 818 area coderegion would be handled as follows: On the switching level, the originalarea code, for example "818", will be known as 818-A and the first levelof overlay will be known as 818-B, etc. After the central officereceives the traditional 7 digits, there will be a courtesy pause of 3to 7 seconds, which will allow the user to enter a `0` or `1` ornothing. If no 8th digit is entered, the system assumes `0` and directsthe call to 818-A. This feature allows all existing phone numbers tostill be accessible by dialing only the original 7 digit number. If a`0` is entered, the system also directs the call to 818-A. If a `1` isentered, the system directs the call to 818-B. Once the number arrivesat 818-A or 818-B, it is switched at the central office as a normal 7digit number (the new 8th digit is ignored at this level--it was onlynecessary in determining which of the overlaid area codes to access). Onthe dialing level, for example, 818-A can be accessed the same asalways, by dialing only the 7 digit phone number. The 8th digit `0`could be added by the user, but it is not mandatory. Thus nodirectories, stationary, auto dialing systems, etc., need to be changed.818-B will be accessed when the user supplies a `1` for the 8th digit.These new numbers will always be known to the users as 8 digit phonenumbers, and so no existing databases will need to be updated.

In this alternate variation, calls coming into the region from outsideof the region will be handled as follows: On the switching level, whenan out of region call is initiated with a 0 or a 1 (to access longdistance or operator services), the phone system normally listens forthe completion of a 10 digit number. i.e. 818-956-3360. With thisvariation of the invention, the phone system will listen for thetraditional 10 digits, and will then supply a courtesy pause of 3 to 7seconds which will give the opportunity for the user to enter an 11thdigit (if necessary). The 10 or 11 digit phone number will then berouted to the appropriate destination area code. If the call wasintended for 818, when it arrives at 818 the number is tested for a `0`or `1` suffix in the same manner as described for local calls above. Ifthere is no 8th digit, the system assumes `0` and directs the call to818-A. If the 8th digit is `0`, the system also directs the call to818-A. If the 8th digit is `1`, the system completes the call to 818-B.Once the number arrives at 818-A or 818-B, it is switched at the centraloffice as a normal 7 digit number. On the dialing level, 818-A can beaccessed the same as always, by dialing only 1-818+the original 7 digitphone number. The 8th digit `0` can be added by the user, but it is notmandatory. Thus no out of town directories, auto dialing systems, etc.,need to be updated. 818-B will be accessed when the user dials 1+818+the8 digit phone number, using a `1` for the 8th digit. These new numberswill always be known to the users as 8 digit phone numbers, and so thereis no existing data that needs to be updated. In the future numberingdemands could be met by implementing overlay levels 2 through 9 asneeded.

The unified method and apparatus to simplify telephone area code dialingis a non-disruptive solution for area code relief which is bothcompetitively neutral and consumer friendly. It provides a technicallyworkable alternative for area code relief which minimizes hardship tolocal business and the public.

New numbers can be added to a geographic area without changing the waythat existing numbers are dialed. Established 7 and 1+10 digit dialingpatterns are maintained and a new 8 digit option is enabled which allowsfor abbreviated dialing within and between all area codes in thegeographic overlay area.

Further, the plan demonstrates how dialing parity (mandated by the FCC)can be maintained in an overlay without requiring the full 10 digit (oractually 1+10 digit) phone number to be dialed.

The invention disclosed herein might, at first glance, seem to call upontechniques which previously have been rejected by the TelecommunicationsIndustry and Public Utility Commissions. But a closer examinationdemonstrates that these techniques, as proposed here, solve rather thancreate problems. The cost of implementing the plan for an affectedregion may well be less than the overall cost (cost to business, cost topublic and cost to telecommunications industry) of an area code split.

While only certain preferred features of the invention have beenillustrated and described, many modifications and changes will occur tothose skilled in the art. It is, therefore, to be understood that theappended claims are intended to cover all such modifications and changesas fall within the true spirit of the invention.

I claim:
 1. A method for signalling telephone numbers within, into, andout of an overlay area of a switched telephone network, from a callingtelephone device to a receiving telephone device, said overlay areacomprising a parent area code and at least one child area code, using acomputerized device, comprising the steps of:associating a single-digitparent overlay selector code with said parent area code of said overlayarea; associating a different single-digit child overlay selector codedifferent from said parent overlay selector code, with each of said atleast one child area codes; signalling a call from said callingtelephone device located within said overlay area, using a 7-digittelephone number and an area code associated with an overlay selectorcode, to said receiving telephone device located within said overlayarea and within said parent area code, by detecting the dialing of a7-digit telephone number of said receiving telephone device, detectingthe dialing of said parent overlay selector code, and setting saidoverlay selector code to be said parent overlay selector code, andsignalling a call from said calling telephone device located within saidoverlay area, using said 7-digit telephone number and said area codeassociated with said overlay selector code, to said receiving telephonedevice located within said overlay area and within one of said at leastone child area codes, by detecting the dialing of said 7-digit telephonenumber of said receiving telephone device, detecting the dialing of saidchild overlay selector code, and setting said overlay selector code tobe said child overlay selector code.
 2. The method of claim 1, furthercomprising the step of detecting that a predetermined timing delay haselapsed after detecting the dialing of said 7-digit telephone number,and thereby causing said overlay selector code to default to said parentoverlay selector code, in lieu of detecting the dialing of said parentoverlay selector code.
 3. The method of claim 1, wherein said parentoverlay selector code is a digit "0".
 4. The method of claim 1, whereinsaid computerized device comprises a computerized telephone switch. 5.The method of claim 1, wherein said computerized device comprisescomputerized customer premises equipment.
 6. The method of claim 1,further comprising the steps of:signalling a call from said callingtelephone device located outside of said overlay area, into said overlayarea, to said receiving telephone device located within said overlayarea, by detecting the dialing of an area code of said receivingtelephone device, as well as the dialing of a 7-digit telephone numberof said receiving telephone device; and signalling a call from saidcalling telephone device located within said overlay area, out of saidoverlay area, to said receiving telephone device located outside of saidoverlay area, by detecting the dialing of an area code of said receivingtelephone device, as well as the dialing of a 7-digit telephone numberof said receiving telephone device.
 7. The method of claim 1, whereinsaid area codes are three-digit area codes.
 8. The method of claim 1,wherein determining an area code of said receiving telephone devicecomprises the steps of:if an initial dialed digit is detected to be adigit "2" through "9" inclusive, is not a "0", and is not a "1", thendetermining that said call is to be signalled within said overlay areaand is not an out-of-overlay area call, regarding said initial dialeddigit to be a first digit of a 7-digit local telephone number of saidreceiving telephone device located within said overlay area, detecting aset of remaining 6 digits of said 7-digit local telephone number,detecting said overlay selector code, and signalling a call to saidreceiving telephone device located within said overlay area at a localtelephone number represented by said 7-digit local telephone number, andat an area code represented by said overlay selector code; if saidinitial dialed digit is a digit "0" through "1" inclusive, and is not adigit "2" through "9" inclusive, then determining that an area code isto be provided among the digits to be dialed, and further:detectingfirst, second and third digits following said initial dialed digit;detecting a fourth digit following said initial dialed digit; if saidfourth detected digit following said initial dialed digit is a digit "2"through "9" inclusive, and is not a "0", and is not a "1", regardingsaid fourth digit following to be a first digit of a 7-digit localtelephone number of said receiving telephone device, detecting a set ofremaining 6 digits of said 7-digit local telephone number, andsignalling a call to said receiving telephone device at a three-digitarea code represented by said first, second and third detected digitsfollowing said initial dialed digit, and at a local telephone numberrepresented by the fourth through tenth detected digits following saidinitial dialed digit; if said fourth detected digit following saidinitial dialed digit is a digit "0" through "1" inclusive, and is not adigit "2" through "9" inclusive, regarding said fourth detected digitfollowing to be a fourth digit of a five digit area code, detecting afifth digit following said initial dialed digit to be a fifth digit ofsaid five-digit area code, detecting a set of digits comprising a sixththrough a twelfth digit following said initial dialed digit to be 7digits of a 7-digit local telephone number of said receiving telephonedevice, and signalling a call to said receiving telephone device at afive-digit area code represented by said first through fifth detecteddigits following said initial dialed digit, and at a local telephonenumber represented by the said sixth through twelfth detected digitsfollowing said initial dialed digit.
 9. The method of claim 2, furthercomprising the step of adjusting said predetermined timing delay on acalling telephone device-by-calling telephone device basis.
 10. Themethod of claim 1, further comprising the step of supplementing saidsingle-digit overlay codes with a second overlay selector code digit.11. A method for signalling telephone numbers in a switched telephonenetwork, from a calling telephone device to a receiving telephonedevice, by means of a computerized device, comprising the steps of:if aninitial dialed digit is detected to be a digit "2" through "9"inclusive, is not a "0", and is not a "1", then determining that saidcall is to be signaled to said receiving telephone device located withina receiving area code that is the same as a calling area code of saidcalling telephone device, regarding said initial dialed digit to be afirst digit of a 7-digit local telephone number of said receivingtelephone device, detecting a set of remaining 6 digits of said 7-digitlocal telephone number, and signalling a call to said telephone devicewithin said area code of said calling device at a local telephone numberrepresented by said 7-digit local telephone number; if said initialdialed digit is a digit "0" through "1" inclusive, and is not a digit"2" through "9" inclusive, then determining that an area code is to beprovided among the digits to be dialed, and further:detecting first,second and third digits following said initial dialed digit; detecting afourth digit following said initial dialed digit; if said fourth digitfollowing said initial dialed digit is a digit "2" through "9"inclusive, and is not a "0", and is not a "1", regarding said fourthdigit following to be a first digit of a 7-digit local telephone numberof said receiving telephone device, detecting a set of remaining 6digits of said 7-digit local telephone number, and signalling a call tosaid telephone device at a three-digit area code represented by saidfirst, second and third digits following said initial dialed digit, andat a local telephone number represented by the fourth through tenthdigits following said initial dialed digit; if said fourth digitfollowing said initial dialed digit is a digit "0" through "1"inclusive, and is not a digit "2" through "9" inclusive, regarding saidfourth digit following to be a fourth digit of a five-digit area code ofsaid receiving telephone device, detecting a fifth digit following saidinitial dialed digit to be a fifth digit of said five-digit area code ofsaid receiving telephone device, detecting a set of digits comprising asixth through a twelfth digit following said initial dialed digit to be7 digits of a 7-digit local telephone number of said receiving telephonedevice, and signalling a call to said receiving telephone device at afive-digit area code represented by said first through fifth digitsfollowing said initial dialed digit, and at a local telephone numberrepresented by the said sixth through twelfth digits following saidinitial dialed digit.
 12. A method for simplifying the dialing of areacodes, from a calling telephone device to a receiving telephone device,said area codes comprising a first area code and at least one additionalarea code, using a computerized device, comprising the stepsof:associating a single-digit first area code selector code with saidfirst area code; associating a different single-digit additional areacode selector code different from first area code selector code, witheach of said at least one additional area codes; signalling a call fromsaid calling telephone device, using a 7-digit telephone number and anarea code associated with an area code selector code, to said receivingtelephone device, by detecting the dialing of a 7-digit telephone numberof said receiving telephone device, detecting the dialing of said firstarea code selector code, and setting said area code selector code to besaid first area code selector code; and signalling a call from saidcalling telephone device, using said 7-digit telephone number and saidarea code associated with said area code selector code, to saidreceiving telephone device, by detecting the dialing of said 7-digittelephone number of said receiving telephone device, detecting thedialing of said additional area code selector code, and setting saidarea code selector code to be said additional area code selector code.13. The method of claim 12, further comprising the step of detectingthat a predetermined timing delay has elapsed after detecting thedialing of said 7-digit telephone number, and thereby causing said areacode selector code to default to said first area code selector code, inlieu of detecting the dialing of said first area code selector code. 14.A computerized device for signalling telephone numbers within, into, andout of an overlay area of a switched telephone network, from a callingtelephone device to a receiving telephone device, said overlay areacomprising a parent area code and at least one child area code,comprising computerized means for:associating a single-digit parentoverlay selector code with said parent area code of said overlay area;associating a different single-digit child overlay selector codedifferent from said parent overlay selector code, with each of said atleast one child area codes; signalling a call from said callingtelephone device located within said overlay area, using a 7-digittelephone number and an area code associated with an overlay selectorcode, to said receiving telephone device located within said overlayarea and within said parent area code, by detecting the dialing of a7-digit telephone number of said receiving telephone device, detectingthe dialing of said parent overlay selector code, and setting saidoverlay selector code to be said parent overlay selector code; andsignalling a call from said calling telephone device located within saidoverlay area, using said 7-digit telephone number and said area codeassociated with said overlay selector code, to said receiving telephonedevice located within said overlay area and within one of said at leastone child area codes, by detecting the dialing of said 7-digit telephonenumber of said receiving telephone device, detecting the dialing of saidchild overlay selector code, and setting said overlay selector code tobe said child overlay detector code.
 15. The computerized device ofclaim 14, further comprising computerized means for detecting that apredetermined timing delay has elapsed after detecting the dialing ofsaid 7-digit telephone number, and thereby causing said overlay selectorcode to default to said parent overlay selector code, in lieu ofdetecting the dialing of said parent overlay selector code.
 16. Thecomputerized device of claim 14, wherein said parent overlay selectorcode is a digit "0".
 17. The computerized device of claim 14, whereinsaid computerized device comprises a computerized telephone switch. 18.The computerized device of claim 14, wherein said computerized devicecomprises computerized customer premises equipment.
 19. The computerizeddevice of claim 14, further comprising computerized means for:signallinga call from said calling telephone device located outside of saidoverlay area, into said overlay area, to said receiving telephone devicelocated within said overlay area, by detecting the dialing of an areacode of said receiving telephone device, as well as the dialing of a7-digit telephone number of said receiving telephone device; andsignalling a call from said calling telephone device located within saidoverlay area, out of said overlay area, to said receiving telephonedevice located outside of said overlay area, by detecting the dialing ofan area code of said receiving telephone device, as well as the dialingof a 7-digit telephone number of said receiving telephone device. 20.The computerized device of claim 14, wherein said area codes arethree-digit area codes.
 21. The computerized device of claim 14, furthercomprising computerized means for determining an area code of saidreceiving telephone device by:if an initial dialed digit is detected tobe a digit "2" through "9" inclusive, is not a "0", and is not a "1",then determining that said call is to be signalled within said overlayarea and is not an out-of-overlay area call, regarding said initialdialed digit to be a first digit of a 7-digit local telephone number ofsaid receiving telephone device located within said overlay area,detecting a set of remaining 6 digits of said 7-digit local telephonenumber, detecting said overlay selector code, and signalling a call tosaid receiving telephone device located within said overlay area at alocal telephone number represented by said 7-digit local telephonenumber, and at an area code represented by said overlay selector code;if said initial dialed digit is a digit "0" through "1" inclusive, andis not a digit "2" through "9" inclusive, then determining that an areacode is to be provided among the digits to be dialed, andfurther:detecting first, second and third digits following said initialdialed digit; detecting a fourth digit following said initial dialeddigit; if said fourth detected digit following said initial dialed digitis a digit "2" through "9" inclusive, and is not a "0", and is not a"1", regarding said fourth digit following to be a first digit of a7-digit local telephone number of said receiving telephone device,detecting a set of remaining 6 digits of said 7-digit local telephonenumber, and signalling a call to said receiving telephone device at athree-digit area code represented by said first, second and thirddetected digits following said initial dialed digit, and at a localtelephone number represented by the fourth through tenth detected digitsfollowing said initial dialed digit; if said fourth detected digitfollowing said initial dialed digit is a digit "0" through "1"inclusive, and is not a digit "2" through "9" inclusive, regarding saidfourth detected digit following to be a fourth digit of a five digitarea code, detecting a fifth digit following said initial dialed digitto be a fifth digit of said five-digit area code, detecting a set ofdigits comprising a sixth through a twelfth digit following said initialdialed digit to be 7 digits of a 7-digit local telephone number of saidreceiving telephone device, and signalling a call to said receivingtelephone device at a five-digit area code represented by said firstthrough fifth detected digits following said initial dialed digit, andat a local telephone number represented by the said sixth throughtwelfth detected digits following said initial dialed digit.
 22. Thecomputerized device of claim 15, further comprising timing delayadjustment means for adjusting said predetermined timing delay on acalling telephone device-by-calling telephone device basis.
 23. Thecomputerized device of claim 14, wherein said single-digit overlay codesare supplemented by a second overlay selector code digit.
 24. Acomputerized device for signalling telephone numbers in a switchedtelephone network, from a calling telephone device to a receivingtelephone device, comprising computerized means for:if an initial dialeddigit is detected to be a digit "2" through "9" inclusive, is not a "0",and is not a "1", then determining that said call is to be signalled tosaid receiving telephone device located within a receiving area codethat is the same as a calling area code of said calling telephonedevice, regarding said initial dialed digit to be a first digit of a7-digit local telephone number of said receiving telephone device,detecting a set of remaining 6 digits of said 7-digit local telephonenumber, and signalling a call to said telephone device within said areacode of said calling device at a local telephone number represented bysaid 7-digit local telephone number; if said initial dialed digit is adigit "0" through "1" inclusive, and is not a digit "2" through "9"inclusive, then determining that an area code is to be provided amongthe digits to be dialed, and further:detecting first, second and thirddigits following said initial dialed digit; detecting a fourth digitfollowing said initial dialed digit; if said fourth digit following saidinitial dialed digit is a digit "2" through "9", inclusive, and is not a"0", and is not a "1", regarding said fourth digit following to be afirst digit of a 7-digit local telephone number of said receivingtelephone device, detecting a set of remaining 6 digits of said 7-digitlocal telephone number, and signalling a call to said telephone deviceat a three-digit area code represented by said first, second and thirddigits following said initial dialed digit, and at a local telephonenumber represented by the fourth through tenth digits following saidinitial dialed digit; if said fourth digit following said initial dialeddigit is a digit "0" through "1" inclusive, and is not a digit "2"through "9" inclusive, regarding said fourth digit following to be afourth digit of a five-digit area code of said receiving telephonedevice, detecting a fifth digit following said initial dialed digit tobe a fifth digit of said five-digit area code of said receivingtelephone device, detecting a set of digits comprising a sixth through atwelfth digit following said initial dialed digit to be 7 digits of a7-digit local telephone number of said receiving telephone device, andsignalling a call to said receiving telephone device at a five-digitarea code represented by said first through fifth digits following saidinitial dialed digit, and at a local telephone number represented by thesaid sixth through twelfth digits following said initial dialed digit.25. A computerized device for simplifying the dialing of area codes,from a calling telephone device to a receiving telephone device, saidarea codes comprising a first area code and at least one additional areacode, comprising computerized means for:associating a single-digit firstarea code selector code with said first area code; associating adifferent single-digit additional area code selector code different fromfirst area code selector code, with each of said at least one additionalarea codes; signalling a call from said calling telephone device, usinga 7-digit telephone number and an area code associated with an area codeselector code, to said receiving telephone device, by detecting thedialing of a 7-digit telephones number of said receiving telephonedevice, detecting the dialing of said first area code selector code, andsetting said area code selector code to be said first area code selectorcode; and signalling a call from said calling telephone device, usingsaid 7-digit telephone number and said area code associated with saidarea code selector code, to said receiving telephone device, bydetecting the dialing of said 7-digit telephone number of said receivingtelephone device, detecting the dialing of said additional area codeselector code, and setting said area code selector code to be saidadditional area code selector code.
 26. The computerized device of claim25, further comprising computerized means for detecting that apredetermined timing delay has elapsed after detecting the dialing ofsaid 7-digit telephone number, and thereby causing said area codeselector code to default to said first area code selector code, in lieuof detecting the dialing of said first area code selector code.